Can the CPU limit RAM Usage?

[Guest]

Upgrading mobo to...

Brand BIOSTAR
Model TA760G M2+
Supported CPU
CPU Socket Type AM2+/AM2
CPU Type Phenom / Athlon 64 X2 / Athlon 64 / Sempron
FSB 2600MHz Hyper Transport (5200 MT/s)
Chipsets
North Bridge AMD 760G
South Bridge AMD SB710
Memory
Number of Memory Slots 4×240pin
Memory Standard DDR2 1066
Maximum Memory Supported 16GB
Channel Supported Dual Channel

...and decided to upgrade memory to...

CORSAIR DOMINATOR 4GB 2X2GB PC2 8500 DDR2

...and my current CPU is...

Athlon 64 X2 4000
Tech Spec
Core Brisbane
Multi-Core Dual-Core
Operating Frequency 2.1GHz
Hyper Transports 2000MHz
L1 Cache 128KB+128KB
L2 Cache 2 x 512KB

My question is this, is this CPU capable of using all this RAM, or does it not matter? If so, how does one know how much RAM a CPU can use? If not, is it just the mobo that limits RAM usage?

 

[hellwig]

The CPU will not limit the amount of RAM being used in your system. The processor is capable of addressing far more ram than you could fit into that motherboard. The 16GB limit is imposed by the motherboard BIOS, but since you can hardly find 4GB dimms anyway, don't worry about it.

What WILL limit your memory usage is the operating system you choose. If you install a 32-bit version of Windows, you will not see all 4GB of your memory. If you install a 64-bit version of Windows, all 4GB will be available to you.

 

[Guest]

Am using Windows XP Home Ed. w/ SP2. How do I know what "bit" version I have?? I have disk, lable, and original packaging, none of which mention the "bit" version.

 

[hellwig]

There is no 64-bit version of Windows XP Home. Unless the disk says "Windows XP Professional x64", you are using a 32-bit version of the Win XP. This means when you turn on your computer and check the system settings (i.e. right-click on My Computer), you will only see about 3-3.2GB of memory. 32-bit windows is unable to address the remainder of your physical memory because it uses those addresses for other system settings.

However, this isn't really a problem. Using a dual-channel 4-GB kit will still be better than a 2-GB kit (you get an extra gig out of it). It's also better than running 3GB without dual-channel mode (because dual-channel is twice as fast).

If you upgrade to Vista 64-bit or Win 7 64-bit (avoid Win Xp Pro x64, it's not well supported), you will see all 4GB of memory (but some things will also use more memory, being that the OS is 64-bit versus 32-bit).

I would stick with your planned upgrades, even if you stick with Win XP Home.

 

[Guest]

Thank you for your help, I'm new to this and am just a little nervous. I got nervous because Newegg's overview of this CPU says "This versatile processor is designed to enable next-generation platform innovations like AMD Virtualization and high-performance, un-buffered DDR2 memory (supporting up to DDR2 800) to the award-winning AMD64 architecture." I assume the RAM I bought is DDR2 1066 which is higher?

 

[hellwig]

Oh, DDR2 800 is referring to the speed of the memory, not the size or capacity. Some AMD processors (older Athlons/Semprons) only support DDR2-800 or slower speeds.

Your DDR2-1066 memory is capable of running a little faster than the processor wants to, but that is not a problem. Your processor will limit the speed of your memory, but you won't notice much of a difference between DDR2-800 and DDR2-1066. Your memory will automatically run at the slower speeds just fine.

 

[Guest]

One more dumb question...Why do mobo's support 16GB of memory if almost everyone runs a 32 bit system that only allows the use of 3.2GB's? Thanks again!

 

[burn-e86]

There is no 64-bit version of Windows XP Home. Unless the disk says "Windows XP Professional x64", you are using a 32-bit version of the Win XP. This means when you turn on your computer and check the system settings (i.e. right-click on My Computer), you will only see about 3-3.2GB of memory. 32-bit windows is unable to address the remainder of your physical memory because it uses those addresses for other system settings.

However, this isn't really a problem. Using a dual-channel 4-GB kit will still be better than a 2-GB kit (you get an extra gig out of it). It's also better than running 3GB without dual-channel mode (because dual-channel is twice as fast).

If you upgrade to Vista 64-bit or Win 7 64-bit (avoid Win Xp Pro x64, it's not well supported), you will see all 4GB of memory (but some things will also use more memory, being that the OS is 64-bit versus 32-bit).

I would stick with your planned upgrades, even if you stick with Win XP Home.

actually dual channel are on average 3~5% faster, not double the speed.

as to the mobo's supporting 16 Gb, hardware and software devs are pushing for 64bit OS. a 64 bit OS is capible of supporting for all intents and purposes an unlimited amount of memory. also while most motherboards are capible of supporting 16Gb most will only be able to fit a max of 8 Gb (4x 2Gb). 64bit also means that devs will be able to address more memory.

 

[loneninja]

One more dumb question...Why do mobo's support 16GB of memory if almost everyone runs a 32 bit system that only allows the use of 3.2GB's? Thanks again!

Actually there is a rapidly growing number of people using 64bit and a rather high number of computers have been selling with 4-8Gb of ram and Vista 64bit in them for awhile now.

 

[rand_79]

dual channel is double the memory bandwidth, 3-5% faster overall computer speed(on average)